SY88149NDL 1.25Gbps Burst-Mode Limiting Amplifier with Ultra-Fast Signal Assert Timing Features General Description <5ns SD Assert (LOS Deassert) time The SY88149NDL is a high-sensitivity, burst-mode Option to AUTO RESET or manual RESET LOS/SD capable limiting post amplifier designed for Optical Line output Terminal (OLT) receiver applications. The SY88149NDL satisfies the strict timing restrictions of the GPON Selectable LOS/SD output option standards by providing ultra-fast Loss-of-Signal (LOS) or High-sensitivity LOS/SD signal detect Signal-Detect (SD) output. Auto Reset and Manual Reset Low-noise LVPECL data outputs options are provided to control LOS/SD output timing. For Squelching function to maintain output stability increased flexibility, this device also includes an option to select between LOS or SD output. The device can be Programmable LOS/SD level set (LOS/SD ) LVL connected to burst-mode capable transimpedance 5mVpp input sensitivity amplifiers (TIAs) using AC or DC coupling. 1.25Gbps operation The SY88149NDL generates a high-gain LOS or SD Single 3.3V power supply LVTTL output. A programmable LOS/SD level set pin Available in a 16-pin (3mm 3mm) QFN package (LOS/SD ) sets the sensitivity of the input amplitude LVL detection. When LOS/SD SEL pin is left open or tied to Applications Vcc, JAM is active high, SD is selected and asserts high if the input amplitude rises above the threshold sets by GE-PON/GPON OLT LOS/SD and de-asserts low otherwise. When LOS/SD LVL Gigabit Ethernet SEL pin is set low or tied to GND, JAM is active low, LOS Fibre Channel is selected and asserts low if the input amplitude rises OC-3/12/24 SONET/SDH above the threshold sets by LOS/SD and de-asserts LVL high otherwise. The LOS/SD output can be fed back to the High-gain line driver and line receiver JAM input to maintain output stability under an invalid Low-gain TIA interface signal conditions. Typically, 45 dB SD hysteresis is provided to prevent chattering. Markets The SY88149NDL also features a selectable proprietary FTTH PON Noise Discriminator that aids by filtering out input signals Datacom/Telecom that do not qualify as a 1.25Gbps GPON preamble signal in the initial startup phase. This feature minimizes false SD Optical transceiver Asserts that can be triggered by random noise. The SY88149NDL operates from a single +3.3V power o o supply, over temperatures ranging from 40 C to +85 C. With its wide bandwidth and high gain, signals up to 1.25Gbps and as small as 5mVpp can be amplified to drive devices with LVPECL inputs. All support documentation can be found on Micrels web site at: www.micrel.com. Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. SY88149NDL Ordering Information Part Number Package Type Operating Range Package Marking SY88149NDLMG Lead-Free QFN-16 Industrial 149N with Pb-Free bar-line indicator (1) SY88149NDLMG TR Lead-Free QFN-16 Industrial 149N with Pb-Free bar-line indicator Notes: 1. Tape and Reel. Pin Configuration 16-Pin QFN (QFN-16) Truth Table for SD/LOS Select and Noise Discriminator function LOS/SDSEL PIN LOS/SD SELECTION NOISE DISCRIMINATOR INPUT TO JAM OUTPUTS 0 to VCC SD Enabled HIGH Enabled 0 to VCC SD Enabled LOW Disabled 16K to VCC SD Disabled HIGH Enabled 16K to VCC SD Disabled LOW Disabled 16K to GND LOS Disabled HIGH Disabled 16K to GND LOS Disabled LOW Enabled 0 to GND LOS Enabled HIGH Disabled 0 to GND LOS Enabled LOW Enabled M9999-020712-A February 2012 2 hbwhelp micrel.com or (408) 955-1690